Calling device identification cam assembly



Feb. 4, 1958 J. E. OSTLINE 2,322,424

CALLING DEVICE IDENTIFICATION CAM ASSEMBLY Filed Dec. 2, 1954 INVENTOR.Jon" E. os rum:

'ATTY.

United States Patent O CALLING DEVICE IDENTIFICATION CAM ASSEMBLY JohnE. Ostline, Chicago, 111., assignor to General Telephone Laboratories,Incorporated, a corporation of Delaware Application December 2, 1954,Serial No. 472,713

9 Claims. (Cl. 17990) This invention relates to calling devices of theimpulse transmitting type and more particularly to improvements in partyidentification cam arrangements adapted for use in such calling devices.The calling device of the charac- ;ter in which the use of the presentinvention is contemsupplemental impulsing spring operating pawl that thelatter springs will make contact at a time bearing a predeterminedrelationship to the contact of the digit impulsing springs as operatedby the digit impulse ispindle 1 and cam.

It is evident from the arrangement shown in my cited patent that theangular positioning of the supplemental impulsing cam is highly criticalif the predetermined relationship referred to is to be accuratelymaintained. As shown in that patent the positioning is accomplished byshifting the cam lobe or lobes about the axis of the main dial arbor toproperly correspond with the timing of the digital impulses. lobesdepends for its accuracy of locating the lobes largely upon trial anderror and is therefore from the view point of convenience and facilityof adjustment, and to that extent, not wholly satisfactory.

Further, party identification cam assemblies of the type embodied in thedialing device of my patentreferred to have'been limited to theparticular telephone systems for which they have been designed. Theidentification cam assembly of the cited patent, for example, having amaximum of three cam lobes is applicable only to the system described,that is, a system including an exchange in which the party subscriberlines each have a maximum of four party subscriber substationsassociated therewith. The cam assembly cannot be made readily applicableto a system, for example, having party subscriber lines each' subscribersubstations associated of which has ten party therewith.

Accordingly, it is the chief object of my invention to proper timing ofthe operation of the identification springs with respect to theoperation of the digit impulsing' springs.

ltis another object of my invention to provide in a calling device anidentification cam assembly which is This method of shifting the camuniversally applicable to telephone systems requiring a supplementaryimpulse or series of impulses for identification purposes.

A further object of my invention is the provision of a durable camassembly of the type described in the preceding paragraph which issimple and sturdy in construction and economical to manufacture and thecomponent parts of which are held to a minimum.

Still another object of this invention is to provide a cam assembly ofthe type'described which with a mini mum nu'mber of operations can beadapted to transmit either noneor any number. of supplementaryidentification impulses up to a'maximum of ten such impulses as maybe'required by thejsystern in which the calling device is employed. 5 Afeature ofthis invention is a novel cam locating plate having indexingmeans designed to insure the positive and accurate positioning of theidentification cam. Other objects and features of my invention willbecome apparent froma reading of the detailed description which followstaken in conjunction with the accompanying drawings of which: Q 7 I Fig.1 is a plan view of the rear ofa dialing device showing the relativepositions of the contact springs and the two operating cams, v

Fig. 2 is a side elevation of the dialing device showing clearly thepair'of supplementary impulsing springs and their relation to the maindial arbor operated cam, h Fig. 3 is an enlarged plan view of theidentification cam assembly showing the supplementary contact springsand cam arrangement, the operating meansemployed to actuate the'springs,and the cam lobe locating means, aiid.

Fig. 4 is a sectional view along the line 44 ofFig. 3 showing therelative positions of the details of the identifica'tion cam assembly. ii 'A dialing device embodying my invention and shown in Figs..l and 2includes a mechanism housinglll and'a finger wheel ll'and dial plate12'which may be 'operaf tively secured to the housing 10 anditscontained teach: anism (not shown) in awell-known manner Q 'Amain arbor13 rotatably mounted in the housing 10 isrotatable with the finger wheel11 and carriesthe identification cam assembly to be described in detailhereinafter. 'The usual" coil spring 14 atfixed at one end to thehousing 10 and at the other end to the arbor l3 insures the return to anormal position of the finger wheel 11 after it has been' rotated apredetermined amount. A 'spindle'lS extends outside of the housing 10parallel to the arbor 13 and is controlled by the mechanismto rotate,"only" upon the release of the finger wheel 11 when the vfinger wheel 11is permitted to return to its normal-position." An im'-' pulsing cam 16is rigidly secured'to the spindle 15 in anyconvenient manner as by thelock nuts 17. A centrifugal governor arrangement 18 mountedpn thehousing10 is associated. witha. gear'19 also: rigidly secured on thespindle 15 to-maintain the rotational speed ofxthe cam 16 withinpredetermined limits in a well-known manner; r

Mounted on the housing .10 ina conventionalmanner as by thescrew meansas shown and appropriately insulated from each other where necessaryarea number of operating spring assemblies. Two of these springs, 20 and21, are impulsing springs operatively associated with-- a pair of lobes22 of the impulsing cam1 6. An impulse. spring control arm 23 rigidlysecured to thearbor 13 in' a manner to be more specificallydescribed isprovidedto engage a buffer 24 on thespring 21 to hold the impulsesprings20. and 21 closed and out'of-engagement witlr the cam 16 whilethehfingere wheel 11 is-in its normal. position. Additional, springs,25, 26, and.27, comprisev the shunt springs, spring 27 being providedwith a bu fier 28 which-is adapted to. cooperateewithfa shunt spring,

Patented Feb. 4,1958,

amanner to be describedlater, to hold the shunt springs open whilethe'fingerwheel 11 is-inits normal-position.

A pair of supplementary impulsing springs 30 and 31 completes the groupof operating springassemblies. As most clearly shown in Fig: 2 thespring 30 carriesits contactohaslightly ofi-set portion of theispring;:The spring31 is mounted in the spring pile-upiincluding'the shuntsprings 25, 26- and '27, by means offa perpendicularly projecting leg31;: and ispositionedsubstantially out of the lateral plane "of thespring 30forreasons which will becomeapparent herein. The contact of thespring 31 is carriedon an ofi=setprovided on the spring 31 to meet theoihset portionof the spring 30; 7

Referring to Fig. 3, the spring 31 is seen-tohave two parallel, inwardlydirected tabs 31b between the facing sides of which the spring 31 is cutaway as at 31c and 31d. A pawl 32 pivotally mounted between the 'tabs31b by means of a pin 33 is held in a normal, nonoperated-position bymeansof a fiat spring 34 operating against a lug 35. The lug 35 is heldflat against the spring 31 by the spring 34 in such a manner asvto'resist the clockwise rotation of the pawl 32 as viewed in 'Fig. 3.Obviously counter clockwise rotation is prevented .entirely by thecontact of the lug 35 against the surface of the spring 31.

Cooperating with the supplementary impulsing springs 30 and 31'is anidentification cam assembly mounted on the arbor 13 previouslydescribed. The arbor 13 is journalled in a guide bushing 36 afiixed tothe housing 10. A second bushing 37 mounted on thearbor 13 and:rotatable therewith provides a means for securing-the impulse springcontrol arm 29 previously described. The control arms may be afiixed toor be integral with-a washer 39 which is seated on an annular shoulderprovided on the bushing 37, the washer 39 being rotatable with the saidbushing 37. Securely supported by the washer 39 and rigidly mounted onthe bushing 37 in any convenient manner as by upsetting the upperportion .of the bushing 37 is an annular cam mounting plate 38.:Concentric with the annular mounting plate 38 and the arbor 13 is aninsulated annular cam 40 resting on the plate 38 and the arbor 1-3 is,an insulated annular cam 40 resting 'on the plate 3.8 and having aperipheral portionextending beyond the plate 38. A cam lobe 41 isprovided on the periphery of the cam 40. Although only-one 'lobe isshown :it is to be understood that any number of such lobes maybeprovided as .may be required for identification purposes. An-annular camguide plate-42 also testing on the mounting plate 38 maintains thecam-40 in its concentric relation with the arbor 13 and'also provides asurface about which the annular cam 40 may be angularly shifted. Acircular'cam locating plate 43 resting on-the annular-cam 40alsoconcentric with the arbor 13 and the cam 40 completes theidentification cam assembly. Maintaining the cam assembly rigidly "inthe relationship described are the mounting screws"44. In

the preferred embodiment of my invention three such screws preferablyseparated'by-l20 are :found tobe sat-' Fig, 3. Thus the cam lobe orlobes 41 may be rotated,

about the' annular cam guide plate 42 to a position or positionsdirectly opposite any one or more of'the notches 45; Indicia 46indicatin -the notches 45 may be provided on the surface, of the plate43 to facilitate the lqcation of thfefrequired lobe position. When the:cam lobe 41 f the present, embodiment has been shifted tithe requiredposition bpposite one. ofgthe locating notches 4:5 the" screws 44 mayhesecured thnsclarnping theannular cam 40"rigidly b t e n h ccat nap a e'43 and t e; meant e slightly under that of the cam 40 to insure thatthe locat- 'ing-plate-43 will' bearonlyon-the cam-40.

The pawl 32 together with the springs 30 and 31 is so positioned withrespect to the identification cam assembly that when the arbor 13 andthe cam 40 are rotated far enough in either a clockwise or a counterclockwise direction, the cam lobe 41-wil1"engage the pawl 32. Howe enwhen'th e he Bend cam -49" 1t t dw counter clockwise direction as viewedin Fig. 3, that is, when the finger wheel 11 is rotated from its normalpositionpthe lobe 41 by engaging the pawl 32 causes it't'o pivot aboutthe pin 33 in a clockwise direction. There will, in this case, be noappreciable eifect on the spring 31 since the bias ot the spring 341snotsufiicienttto prevent the pawl 32 from pivoting by its contact withthe lug 35. When the cam 40, on the otherhand, is rotated in a clockwisedirection as viewed in Fig. 3, that is, when the finger wheel isreleased after rotation and permitted to return to its normalpositio'n,'the'lobe 41 again engages into contact with the spring 30. Assoon as the lobe 41 in its clockwise rotation passes the pawl 32 thespring 31 .willlreturn to normal, that is, out of contact with theSpring 30,.by its. own spring action. To prevent the spring/"311mmreturning too far and thereby to prevent any possible contact of thepawl 32 with the cam 40 proper during its rotation an additionalfiatspring 47 mounted in the same manner as the spring 31 is pro- Vided. Thespring 47 biases the spring 31 and the pawl 3,2only sulficiently tomaintain a minimal distance from the cam .40 proper but not enough tocause the springs 30 and 31 to make contact.

Returning now to theoperationof the dialing device: as thefinger wheel11 is rotated from its normal {position to its extreme rotatableposition, that is, to a position corresponding to the 0 digit of aconventional auto.-

rnatictelephone dialing device, the impulse spring. control.

arm 23 is disengaged fromv the buffer 24, and the closed impulsingsprings 20 and 21 are moved into a cooperative relationship with theimpulsing cam 16. The shunt spring control arm 29 is also disengagedfrom the buffer 28 and the shunt springs 25, 26'and. 27 are closed. The.l b 41 will engage the pawl 23 but, as previously'explained, nooperation of thesprings 30 and 31 is effected. By the/operation of theinternal mechanism, not shown, of: the housing 10 no rotation of the cam16 takes place (liming thisrotation .of the. finger wheel 11. When thefinger wheel '11 is released and returned to normal by the tension ofthe :coil spring 14, however, the impulsing cam 16.1'scaused to rotate,the cam lobes 22 alternately engagingihe: spring 20 thereby periodicallyopening the impulsetsprings .20 and 21-which in'turn may periodicallyopen the-iusualllme circuit ofan :automa'tic telephone systemseirtendingthrough the impulse springs 20 and 21.

The centrifugal governor means 18 maintains a uniform speedoflrotationof the impulsing "cam 16 thereby insuring uniformity in thetiming and length of the impulses thus-generated;

'Thie lobe 41 and ithe eam nlay-be sh'i-fted around the guide plate 42to any desired angularp'osition so that the supplementary impulsingsprings 30 and 31 will close at any time with respect to the timingo'fthe opening and the closing of the impulsing springs 20 and 21. In thisembodiment of' the invention, however, it has been contemplated that thesupplementary impulsing springs 30 and 3*1-' be operated alternatelywiththe operation of theimpulsing springs; '20 and 2 1; The notche'sdS, tenin number, are 'therefpre 'spaced around the periphery oft he lo'eating'plate 43 and so located'that-ifthe cam l'obe 4'1 30 and 31 will fallbetween the operation of the impulsing springs 20 and 21. Thepositioning of the lobe 41, for example, as shown in Fig. 3, that isopposite the eighth notch of the cam locating plate 43, will cause thesupplementary impulsing springs 30 and 31 to be operated between theeighth and the ninth operation of the impulsing springs 20 and 21. Thusthe cam assembly as described herein may be employed in telephonecircuit arrangements where it is desired that upon the initial dialingof the digit 0 a single supplementary pulse falling immediately after aselected one of any of the ten digital impulses be generated, theselection of the digit being accomplished merely by shifting the camlobe opposite any one of the locating means 45. In other circuitarrangements a supplementary series of impulses may be desired toalternate or to coincide with the digital impulses generated and this isreadily accomplished by substituting for the cam 40 in the presentlyconsidered assembly a cam having a number of lobes corresponding to thenumber of supplementary impulses desired and then aligning the cam lobeswith the locating means 45 to the desired angular position which in turnwill determine the timing of the supplementary impulses.

The advantages of the cam assembly according to my invention in whichthe parts thereof are interchangeable in the degree described arereadily apparent in terms of economy and simplicity of manufacture. Thusthe only component which will vary in the application of my invention todifferent telephone systems will be the cam 40 and even here some degreeof interchangeability is available. Two cams can thus be used in anyinstallation depending upon the occurrence or non-occurrence ofsupplementary impulses. the cam 40 having no lobes and the cam 40 havingone lobe.

Although that which has been described herein is regarded as thepreferred embodiment of my invention it is to be understood thatmodifications may be made in the operation and structure thereof withoutdeparting from the scope of the appended claims.

What is claimed is:

1. In a dialing device, an impulse generator comprising a rotatableshaft, a finger wheel mounted at one extremity of said shaft formanually rotating said shaft, a mounting plate mounted at the otherextremity of said shaft and rotatable with said shaft, a cam meansadjustably supported on said mounting plate, means for clamping said cammeans to said mounting plate, said clamping means having locatingindicia thereon, and contact spring means including means cooperatingwith said cam means for periodically operating said contact springmeans, adjustment of said cam means with respect to said mounting plateand to said locating indicia controlling the angle of rotation of saidcam means at which said spring means are operated as said shaft and saidcam are rotated.

2. In a dialing device, an impulse generator comprising a rotatableshaft, a finger wheel mounted at one extremity of said shaft formanually rotating said shaft, mounting means perpendicularly andconcentrically secured at the other extremity of said shaft, a camconcentrically supported by said mounting means, a pair of contactsprings associated with said cam, one of said springs having meansthereon for cooperating with said cam, a locating plate havingindicating means thereon, said cam rotatably adjustable on said mountingmeans to correspond with any one of said indicating means, means forclamping said cam rigidly between said locating plate and said mountingmeans after said cam is adjusted, said adjustment of said camdetermining the angle of rotation of said cam means at which saidcontact springs are operated by said cam as said shaft and said cam arerotated.

3. In a dialing device, an impulse generator comprising a rotatableshaft, a finger wheel mounted at one extremity of said shaft, saidfinger wheel adapted for rotating said shaft a predetermined amount,mounting means secured 6 at the other extremity of said shaft and atright angles tothe axis thereof, a cam supported by said mounting meansconcentrically with said shaft, a pair of impulsing springs associatedwith said cam, one of said springs having contacting means thereon forcooperating with said cam, a locating plate having indicating meansthereon, said cam angularly adjustable with respect to the axis of saidshaft on said mounting means to correspond with any one of saidindicating means, and means for clamping said cam between said locatingplate and said mounting means after said cam is adjusted, said camengaging said contacting means as said shaft is rotated to therebyoperate said impulsing springs at a point in the rotation as controlledby the said angular adjustment of said cam.

4. In a dialing device having a rotatable shaft and a finger wheel formanually rotating said shaft a predetermined amount, mounting means atone extremity of said shaft, a circular guide means supported on saidmounting means concentrically with said shaft, an annular cam supportedon said mounting means concentric with said shaft, a locating platehaving indicating means thereon, said annular cam rotatably adjustableabout said circular guide means to correspond with a selected one ofsaid indicating means, means for clamping said annular cam between saidlocating plate and said mounting means, and impulsing spring meansassociated with said cam, said means including means for engaging saidcam as said shaft and said cam are rotated said predetermined amountwhereby said impulsing spring means is operated, the operation of saidimpulsing spring means with respect to the said predetermined amount ofrotation of said shaft being controlled by the said adjustment of saidcam with respect to the said indicating means.

5. In a dialing device according to claim 4, said indicating meanscomprising a sequence of indentations on said locating plate.

6. ln an impulse transmitter comprising periodically operable impulsingsprings and having a rotatable shaft and a finger wheel for manuallyrotating said shaft a predetermined amount, a circular mounting meansconcentrically secured to one extremity of said shaft andperpendicularly to the axis thereof, a circular guide plateconcentrically supported on said mounting means, an annular camassociated with said impulsing springs and concentrically supported onsaid mounting means and rotatable about said circular guide plate, saidcam adapted to operate said impulsing springs as said shaft and said camare rotated, a circular locating plate concentric with said annular camand having indicating means thereon, said indicating means comprising asequence of indentations along the periphery of said locating plate,said annular cam adapted to be rotatably adjusted about said guide plateto a position corresponding to a selected one of said indentations, andmeans for clamping said annular cam between said guide plate and saidmounting means, said adjustment of said cam with respect to saidindicating means determining the angle of rotation of said cam at whichsaid impulsing springs are operated as said shaft is rotated saidpredetermined amount.

7. In an automatic telephone dialing apparatus having supplementaryimpulsing springs and a main dial arbor, a cam assembly for operatingsaid supplementary impulsing springs comprising a mounting plate rigidlysecured to said arbor and concentric therewith, a circular guide platesupported on said mounting plate concentric with said main dial arbor,an annular cam associated with said supplementary impulsing springs andconcentrically supported on said mounting plate, said cam rotatableabout said circular guide plate, a circular locating plate concentricwith said main dial arbor and having indicating means along theperiphery thereof, said cam rotatably adjustable about said plate tocorrespond with said indicatmg means, and means for clamping saidannular cam between said locating plate and said mounting plate.

8. in dialing apparatus according to claim 7, including means formaintaining isaidelocatingplate in =a-.fixed rotary relationwith-saidmountingplate. p 4

9. In anirnpulse transmitting device-havingimpulsing springs and arotatable shaft, a cam assembly comprising a mounting plate secured tothe extremity: of said shaft, a circular guide'plate supported onsaidmounting plate concentric with said shaft, an annular 'cam for operatingsaid impulsing springs as said. shaft is-ro-tated, said..cam supportedon said mountingplate andiencompassing saidguide plate, a circularlocating plate concentric with said shaft, said locating plate 'having asequence of indentations along the periphery thereof, indicia onsaidlocating plate-for designating-said indentations, and'means passingthrough said locating plate, said guide plate and said mounting platefor maintaining said-plates in a fixed rotary relation, said annular camrotatably adjustable about said guide plate to'locate the operatingsurface of said cam intoalignrnent with a selected one of. saidindentations as designated by said indicia, said last-mentioned nieansalso clamping said annular cam betweensaidlocating plate and saidmounting plate, said location of said operating surface with respect tosaid locatingvplate controlling the angle of rotation of said vcarnatwhich said impulsing springs are operated; 1 a a 1 -No references cited.

